Delirium Vs Dementia

A patient with established Alzheimer disease is calm at breakfast, then by evening cannot sustain attention, is drowsy, and tries to climb out of bed. The dementia explains the baseline memory loss and vulnerability; it does not explain that abrupt change. Treat the new change as delirium until an acute cause has been sought. That distinction determines the sequence of care: establish the person’s usual cognition and function, assess attention and arousal, search for physiologic or substance-related precipitants, protect the patient from harm, and only then reassess the chronic cognitive disorder. Delirium and dementia may coexist. A quiet, sleepy patient can have hypoactive delirium, so calm behaviour is not reassurance.